Therapeutic immunization leads to neuroprotection in animal models of HIV-1-associated dementia (HAD) and Parkinson's disease (PD). The mechanism involves modulation of mononuclear phagocyte (MP;macrophages and microglia) inflammation either directly or by regulatory and/or effector T cells. The T-cell-MP interactions protect the brain independent of immune surveillance (anti-retroviral-specific cytotoxic T lymphocytes). The current proposal seeks support to study the mechanisms of how the immune system can be regulated to protect the brain despite a relentless attack by virus and its engagements, independent of anti-retroviral responses. Over the past three of 13 years of this grant cycle significant progress was made in deciphering pathways of how a metabolic encephalopathy is perpetrated through brain MP activation and virus-infection leading to neuronal impairment and cognitive dysfunction. Importantly, this research has evolved and we have been successful in modulating (by glatirimer acetate, GA immunization) a destructive microglia cell to a protective one in murine models of HIV-1 encephalitis. We found that immunization-based neuroprotection involves both innate and adaptive immune systems and that, similar pathways, are operative in animal models of PD making this research broadly applicable in developmental therapeutics for neurodegenerative disorders. Importantly, we now demonstrate that neuroprotection for PD is independent of GA-specific antibody transfers and is T-cell specific. Interestingly, GA elicits innate immune neuroprotection making it potentially useful for patients with significant CD4+ T cell compromise. The work involves an interdisciplinary research approach incorporating immunology, virology, physiology, molecular biology and biochemical approaches used to uncover a microglial profile in health and disease and the means to alter it. Work will proceed from the cell to animal models reflecting HIVE. We posit that effective therapeutic endpoints can be achieved through this work including in immune compromised states and that microglial functional modulation can lead to clinical benefit and new adjunctive therapies in the infected human host.